Effects Of Schisandrin Research Articles

Effects of schisandrin B on hypoxia-related cognitive function and protein expression in vascular dementia rats

ABSTRACT Vascular dementia (VD) a heterogenous group of brain disorders in which cognitive impairment is attributable to vascular risk factors and cerebrovascular disease. A common phenomenon in VD is a dysfunctional cerebral regulatory mechanism associated with insufficient cerebral blood flow, ischemia and hypoxia. Under hypoxic conditions oxygen supply to the brain results in neuronal death leading to neurodegenerative diseases including Alzheimer’s (AD) and VD. In conditions of hypoxia and low oxygen perfusion, expression of hypoxia-inducible factor 1 alpha (HIF-1α) increases under conditions of low oxygen and low perfusion associated with upregulation of expression of hypoxia-upregulated mitochondrial movement regulator (HUMMR), which promotes anterograde mitochondrial transport by binding with trafficking protein kinesin 2 (TRAK2). Schisandrin B (Sch B) an active component derived from Chinese herb Wuweizi prevented β-amyloid protein induced morphological alterations and cell death using a SH-SY5Y neuronal cells considered an AD model. It was thus of interest to determine whether Sch B might also alleviate VD using a rat bilateral common carotid artery occlusion (BCAO) dementia model. The aim of this study was to examine the effects of Sch B in BCAO on cognitive functions such as Morris water maze test and underlying mechanisms involving expression of HIF-1α, TRAK2, and HUMMR levels. The results showed that Sch B improved learning and memory function of rats with VD and exerted a protective effect on the hippocampus by inhibition of protein expression of HIF-1α, TRAK2, and HUMMR factors. Evidence indicates that Sch B may be considered as an alternative in VD treatment.

Schisandrin C improves leaky gut conditions in intestinal cell monolayer, organoid, and nematode models by increasing tight junction protein expression

BackgroundLeaky gut symptoms and inflammatory bowel disease (IBD) are associated with damaged intestinal mucosa, intestinal permeability dysfunction by epithelial cell cytoskeleton contraction, disrupted intercellular tight junction (TJ) protein expression, and abnormal immune responses and are intractable diseases. PurposeWe evaluated the effects of schisandrin C, a dibenzocyclooctadiene lignan from Schisandra chinensis, on intestinal inflammation and permeability dysfunction in gut mimetic systems: cultured intestinal cells, intestinal organoids, and a Caenorhabditis elegans model. MethodsSchisandrin C was selected from 9 lignan compounds from S. chinensis based on its anti-inflammatory effects in HT-29 human intestinal cells. IL-1β and Pseudomonas aeruginosa supernatants were used to disrupt intestinal barrier formation in vitro and in C. elegans, respectively. The effects of schisandrin C on transepithelial electrical resistance (TEER) and intestinal permeability were evaluated in intestinal cell monolayers, and its effect on intestinal permeability dysfunction was tested in mouse intestinal organoids and C. elegans by measuring fluorescein isothiocyanate (FITC)-dextran efflux. The effect of schisandrin C on TJ protein expression was investigated by western blotting and fluorescence microscopy. The signaling pathway underlying these effects was also elucidated. ResultsSchisandrin C ameliorated intestinal permeability dysfunction in three IBD model systems and enhanced epithelial barrier formation via upregulation of ZO-1 and occludin in intestinal cell monolayers and intestinal organoids. In Caco-2 cells, schisandrin C restored IL-1β-mediated increases in MLCK and p-MLC expression, in turn blocking cytoskeletal contraction and subsequent intestinal permeabilization. Schisandrin C inhibited NF-ĸB and p38 MAPK signaling, which regulates MLCK expression and structural reorganization of the TJ complex in Caco-2 cells. Schisandrin C significantly improved abnormal FITC-dextran permeabilization in both intestinal organoids and C. elegans. ConclusionSchisandrin C significantly improves abnormal intestinal permeability and regulates the expression of TJ proteins, long MLCK, p-MLC, and inflammation-related proteins, which are closely related to leaky gut symptoms and IBD development. Therefore, schisandrin C is a candidate to treat leaky gut symptoms and IBDs.

Schisandrin B Protects against Acute Ethanol-Induced Cardiac Injury by Downregulating Autophagy via the NOX4/ROS Pathway

Introduction: Although oxidative stress has been demonstrated to mediate acute ethanol-induced changes in autophagy in the heart, the precise mechanism behind redox regulation in acute ethanol heart disease remains largely unknown. Methods: Wild-type C57BL/6 mice were intraperitoneally injected with ethanol (3 g/kg/day) for 3 consecutive days. The effects of ethanol on cultured primary cardiomyocytes and H9c2 myoblasts were also studied in vitro. Levels of autophagic flux, cardiac apoptosis and function, reactive oxygen species (ROS) accumulation, NOX4, and NOX2 were examined. The NOX4 gene was knocked down with NOX4 siRNA. Results: In this study, we demonstrated that schisandrin B inhibited acute ethanol-induced autophagy and sequent apoptosis. In addition, schisandrin B treatment improved cardiac function in ethanol-treated mice. Furthermore, NOX4 protein expression was increased during acute ethanol exposure, and the upregulation of NOX4 was significantly inhibited by schisandrin B treatment. The knockdown of NOX4 prevented ROS accumulation, cell autophagy, and apoptosis. Conclusion: These results highlight that NOX4 is a critical mediator of ROS and elaborate the role of the NOX4/ROS axis in the effect of schisandrin B on autophagy and autophagy-mediated apoptosis in acute ethanol exposure, which suggests a therapeutic strategy for acute alcoholic cardiomyopathy.

An In-vivo Study into the Effects of Schisandrin B in the Liver, Spleen, Kidney, and Brain of Acute Thioacetamide-intoxicated Mice.

Currently, there are no effective treatments for liver diseases. Treatment usually involves controlling complications and supportive care. As liver injuries also affect other organs such as the spleen, kidney, and brain due to their anatomical and physiological relationships, finding an effective treatment is urgently needed. This research aimed to evaluate the therapeutic effect of Schisandrin B (Sch B) in the liver and other organs in thioacetamide (TAA)-intoxicated mice. In this study, mice were exposed to a single intraperitoneal injection of 200 mg/kg TAA to induce hepatitis. Following Sch B (20 mg/kg/day, 28 consecutive days) treatment, biochemistry analysis and histopathological examination of different organs were performed, in addition to western blotting and flow cytometry to evaluate the involvement of inflammasomes and apoptotic proteins. Our results showed that administration of Sch B protected against TAA-induced damages, and it disparately affected inflammasome activation and apoptosis in different organs. Furthermore, Sch B treatment improved organ function, as indicated by the improvement of serum biochemical parameters. Collectively, our findings reveal a beneficial effect of Sch B on different organ damages in mice intoxicated with TAA.

Schisandrin B improves cerebral ischemia and reduces reperfusion injury in rats through TLR4/NF-κB signaling pathway inhibition

ABSTRACT It has been established that poor outcomes in ischemic stroke patients are associated with the post-reperfusion inflammatory response and up-regulation of TLR4. Therefore, suppression of the TLR4 signaling pathway constitutes a potential neuroprotective therapeutic strategy. Schisandrin B, a compound extracted from Schisandra chinensis, has been shown to possess anti-inflammatory and neuroprotective properties. However, the mechanism remains unclear. In the present study, the therapeutic effect of schisandrin B was assessed following cerebral ischemia and reperfusion (I/R) injury in a model of middle cerebral artery occlusion and reperfusion (MCAO/R) in rats. The effects of schisandrin B were investigated with particular emphasis on TLR4 signal transduction and on the inflammatory response. Schisandrin B treatment conferred significant protection against MCAO/R injury, as evidenced by decreases in infarct volume, neurological score, and the number of apoptotic neurons and inflammatory signaling molecules. Abbreviations I/R: schemia/reperfusion; IL: interleukin; MCAO/R: middle cerebral artery occlusion and reperfusion; NF-κB: nuclear; TLR4: Toll-like receptor 4; TNF-α: tumor necrosis factor-α

Schisandrin B attenuates bleomycin-induced pulmonary fibrosis in mice through the wingless/integrase-1 signaling pathway

Purpose/Aim: Pulmonary fibrosis (PF) is characterized by the progressive and ultimately fatal accumulation of fibroblasts and extracellular matrix in the lung that distorts its architecture and compromises its function.Objective: The present study investigated the potential protective effects of schisandrin B (Sch B) on the Wingless/Integrase-1 (Wnt) signaling pathway in attenuating inflammation and oxidative stress in ICR mice.Methods: Sixty healthy ICR mice were randomly divided into the following groups: control group, bleomycin (BLM) group, Sch B low dose (Sch B-L) group, Sch B medium dose (Sch B-M) group, Sch B high dose (Sch B-H) group, and dexamethasone (DXM) group. The expression of transforming growth factor (TGF)-β1 was examined by ELISA. In addition, the levels of superoxide dismutase (SOD), hydroxyproline (HYP), and the total antioxidant capacity (T-AOC) were determined. The protein and mRNA levels of matrix metalloproteinase 7 (MMP7) and β-catenin in mice were analyzed by western blot and quantitative real -quantitative time PCR (qRT-PCR), respectively.Results: Lung tissues from the BLM group exhibited significantly more inflammatory changes and a significantly greater number of collagen fibers than lung tissues from the control group. In addition, the lung tissues from these BLM-treated mice exhibited slightly increased MMP7 and β-catenin protein expression. Lung tissues from the Sch B-H group exhibited fewer inflammatory changes and fewer collagen fibers than lung tissues from the BLM group. Furthermore, the lung tissues from the Sch B-H mice exhibited decreased HYP and TGF-β1 levels, but increased SOD and T-AOC levels.Conclusions: The present study provided evidence that Sch B may be a potential therapeutic agent for the treatment of PF.

Schisandrin A Inhibits the IL-1β-Induced Inflammation and Cartilage Degradation via Suppression of MAPK and NF-κB Signal Pathways in Rat Chondrocytes.

Osteoarthritis (OA) is a common joint disease in the elderly population. Its development has been reported to be associated with cartilage degradation and inflammatory responses. Schisandrin A, a bioactive lignin in Schisandra sphenanthera, has shown its anti-inflammatory potential in various inflammation diseases. However, the effects of Schisandrin A on OA remain to explore. In this study, rat chondrocytes were treated with IL-1β (10 ng/ml) with or without different concentrations of Schisandrin A for 24 h. Cell viability was evaluated by CCK-8 assay. Production of nitric oxide (NO) and prostaglandin E2 (PGE2) was measured by the Griess reaction and ELISA. The MAPK/NF-κB-related signaling molecules expression and the protein production of inducible nitric oxide synthase (iNOS), cyclooxygenase (Cox)-2, MMPs (MMP1, MMP3, MMP13), ADAMTS5, Collagen II, aggrecan, and Sox9 were detected by Western blot. Protein expression of Collagen II, aggrecan, and p65 nuclear translocation was evaluated by immunofluorescence. In vivo, intra-articular injection of 50 μM Schisandrin A or equal volume of vehicle was performed on rat OA models. Severity of cartilage damage was evaluated by HE and Safranin-O-Fast green staining. Our results revealed that Schisandrin A could suppress the IL-1β-induced production of NO and PGE2 in rat chondrocytes. Consistent with these findings, the upregulation of iNOS and Cox2 could also been decreased by Schisandrin A. Additionally, Schisandrin A could inhibit IL-1β-induced cartilage matrix catabolic enzymes including MMPs and ADAMTS5. Moreover, the IL-1β-induced downregulation of Collagen II, aggrecan, and Sox9 could be ameliorated by Schisandrin A. Mechanistically, Schisandrin A functioned by suppressing MAPK and NF-κB signal pathways. In vivo, Schisandrin A prevented cartilage damage in rat OA model. In conclusion, this study elucidates that Schisandrin A inhibits the IL-1β-induced inflammation and cartilage degradation via suppression of MAPK and NF-κB signal pathways, indicating its potential role in OA therapy.

Schisandrin B induces growth inhibition and apoptosis of human Ewing sarcoma cells in vitro

Objective To investigate the effect of Schisandrin B (Sch B) on growth inhibition and apoptosis of human Ewing sarcoma cells in vitro, and to explore its possible mechanism. Methods Ewing sarcoma cell line A673 was treated with Sch B in vitro. The inhibitory effect of Sch B on the proliferation of Ewing sarcoma cells was studied by methyl thiazol tetrazolium (MTT) assay (0, 10, 20, 50, 100 μmol/L). Colony forming experiment was used to explore the inhibitory effect of Sch B on the colony formation of Ewing sarcoma cells (0, 5, 10, 15 μmol/L). The expression of B cell lymphoma/leukemia-2 (bcl-2), bcl-2 associated X protein (bax), p53 and Cyclin D1 protein was detected by Western blotting (10, 20, 50 μmol/L). Results The results showed that Sch B effectively inhibited cell growth and induced apoptosis of human Ewing sarcoma cell line A673 (18.22%, 22.50%, 34.43%, 53.56%) in a time- and dose-dependent fashion. Sch B also significantly inhibited the colony forming ability of Ewing sarcoma cells (110.5±12.4, 82.2±14.1, 54.3±9.2, 38.4±16.5). Sch B could significantly down-regulate the expression of bcl-2 and Cyclin D1n, and significantly up-regulate the expression of bax and p53. Conclusion Our findings demonstrate that Sch B can significantly inhibit the proliferation of Ewing sarcoma cell line A673, which may be related with the down-regulation of bcl-2 and Cyclin D1, and up-regulation of bax and p53. Key words: Schisandrin B; Ewing sarcoma; Apoptosis; B cell lymphoma/leukemia-2

Schisandrin C enhances mitochondrial biogenesis and autophagy in C2C12 skeletal muscle cells: potential involvement of anti-oxidative mechanisms.

The molecular study of muscles is needed to overcome chronic inflammation and maintenance of muscles in the human body. Schisandrin C is a pharmacological compound derived from the fruit of Schisandra chinensis and has many characteristics including anti-inflammation, anti-tumor, and anti-oxidation. However, the cellular and molecular mechanisms of Schisandrin C are still not well understood especially in skeletal muscle. Therefore, the present study was evaluated whether the properties of Schisandrin C in C2C12 skeletal muscle cells involved maintenance of cellular homeostasis and protection against oxidative damage. Differentiated C2C12 cells were exposed to H2O2 to induce oxidative stress. The characteristics of anti-oxidants, anti-inflammation, autophagy, and mitochondrial biogenesis were tested by Western blotting. Confocal microscopy was also used to observe mitochondrial activity. Schisandrin C inhibited inflammatory molecules with enhancing anti-oxidant activity and reducing reactive oxygen species (ROS) even in the presence of H2O2. The dual anti-inflammation and anti-oxidant roles of Schisandrin C regulated the translocation of nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor-2 (Nrf-2) to nucleus followed by inhibition of the mitogen-activated protein kinase (MAPK) pathway. Schisandrin C promoted the expression of autophagy and mitochondrial biogenesis molecules. Furthermore, the effect of Schisandrin C increased the mitochondrial activity against oxidative stress. Consequently, the action of Schisandrin C enhanced the regulation of autophagy and mitochondrial biogenesis with potential involvement of anti-oxidative mechanisms including the MAPKs/Nrf-2/heme oxygenase-1 signaling pathway in C2C12 skeletal muscle cells exposed to oxidative stress. Therefore, Schisandrin C may be considered as a beneficial compound for several muscle inflammations.

WITHDRAWN: The anti-growth and anti-metastasis effects of Schisandrin B on hepatocarcinoma cells in vitro and in vivo

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Schisandrin B inhibits the proliferation of airway smooth muscle cells via microRNA-135a suppressing the expression of transient receptor potential channel 1.

Airway smooth muscle cell (ASMC) was known to involve in the pathophysiology of asthma. Schisandrin B was reported to have anti-asthmatic effects in a murine asthma model. However, the molecular mechanism involving in the effect of Schisandrin B on ASMCs remains poorly understood. Sprague-Dawley rats were divided into three groups: rats as the control (Group 1), sensitized rats (Group 2), sensitized rats and intragastric-administrated Schisandrin B (Group 3). The expression of miR-135a and TRPC1 was detected in the rats from three groups. Platelet-derived growth factor (PDGF)-BB was used to induce the proliferation of isolated ASMCs, and the expression of miR-135a and TRPC1 was detected in PDGF-BB-treated ASMCs. Cell viability was examined in ASMCs transfected with miR-135a inhibitor or si-TRPC1. The expression of TRPC1 was examined in A10 cells pretreated with miR-135a inhibitor or miR-135a mimic. In this study, we found that Schisandrin B attenuated the inspiratory and expiratory resistances in sensitized rats. Schisandrin B upregulated the mRNA level of miR-135a and decreased the expression of TRPC1 in sensitized rats. In addition, Schisandrin B reversed the expression of miR-135a and TRPC1 in PDGF-BB-induced ASMCs. Si-TRPC1 abrogated the increasing proliferation of ASMCs induced by miR-135a inhibitor. We also found that miR-135a regulated the expression of TRPC1 in the A10 cells. These results demonstrate that Schisandrin B inhibits the proliferation of ASMCs via miR-135a suppressing the expression of TRPC1.

Schisandrin B Enhances Hepatic/Myocardial Glutathione Regeneration Capacity and Protects Against Oxidant Injury in Rat Livers and Hearts

The effects of schisandrin B (Sch B), curcumin, epigallocatechin gallate (EGCG) and resveratrol on the glutathione regeneration capacity (GRC) of liver and heart tissues ex vivo were examined in relation to their protective effects against CCl4 hepatotoxicity in vivo and myocardial ischemia/reperfusion (I/R) injury ex vivo in rats. Results indicated that Sch B, but not curcumin, EGCG or resveratrol, caused hepatic and myocardial GRC enhancement, which was paralleled by its protection against CCl4 hepatotoxicity and myocardial I/R injury. Although resveratrol and curcumin failed to increase the GRC of liver/heart tissues, they did protect against CCl4 hepatotoxicity and myocardial I/R injury. In conclusion, the Sch B-induced enhancement of GRC ex vivo correlated well with its ability to protect tissues against oxidant injury in vivo/ex vivo, suggesting that the GRC assay can be used as a monitor of tissue protection for compounds stimulating glutathione redox cycling. However, phytochemicals can also protect against oxidant injury through various other

Protective Effect of Schisandrin on Hydrogen Peroxide-Induced Damage in PC12 Cells

In this study, schisandrin was assessed for potential protective effects on pheochromocytoma cell line (PC12 cells). Using PC12 cells damage induced by H2O2(25μmol/L) as in vitro model. After pre-treatment with different concentration of schisandrin (0.3, 0.6, 1.2μM) for 24h, MTT assay was used to detect the cell viability, the supernatant of cells was collected to examine the levels of nitric oxide (NO) in each sample, and immunocytochemical staining was adopted to observe the expression levels of bcl-2. Results showed that schisandrin at different concentrations could increase the viability of PC12 cells and decrease the levels of NO in the culture medium. There were significant differences between schisandrin group and H2O2 group (P<0.05,P<0.01). Immunocytochemical staining result revealed that schisandrin could upregulate bcl-2 protein expression. In summary, schisandrin shown significant neuroprotective effects on H2O2-injured PC12 cells through antioxidant properties and upregulate bcl-2 protein expression, and could be a potential candidate for intervention in neurodegenerative diseases.

Prevention of scopolamine-induced memory deficits by schisandrin B, an antioxidant lignan from Schisandra chinensis in mice

The preventive effect of schisandrin B (Sch B), an antioxidant ingredient of Schisandra chinensis, was studied on scopolamine-induced dementia in mouse. Scopolamine developed oxidative stress in the brain with the decreased levels of antioxidant enzymes and increased nitrite level. At the same time, a significant impairment of learning and memory occurred when evaluated by passive avoidance task (PAT) and Morris water maze (MWM) with concomitant increase of acetylcholinesterase (AChE) activity and decreased acetylcholine levels. Pre-treatment by Sch B (10, 25, 50 mg/kg) effectively prevented scopolamine-induced oxidative stress and improved behavioural tasks. Further, the scopolamine-induced increase in AChE activity was significantly suppressed and the level of acetylcholine was maintained as normal by Sch B treatment. These results suggest that Sch B have protective function against cerebral functional defects such as dementia not only by antioxidant prevention but also exerting its potent cognitive-enhancing activity through modulation of acetylcholine level.

Inhibitory effect of schisandrin on spontaneous contraction of isolated rat colon

This study examined the effect of schisandrin, one of the major lignans isolated from Schisandra chinensis, on spontaneous contraction in rat colon and its possible mechanisms. Schisandrin produced a concentration-dependent inhibition (EC₅₀=1.66 μM) on the colonic spontaneous contraction. The relaxant effect of schisandrin could be abolished by the neuronal Na+ channel blocker tetrodotoxin (1 μM) but not affected by propranolol (1 μM), phentolamine (1 μM), atropine (1 μM) or nicotine desensitization, suggesting possible involvement of non-adrenergic non-cholinergic (NANC) transmitters released from enteric nerves. N(ω)-nitro-l-arginine methyl ester (100-300 μM), a nitric oxide synthase inhibitor, attenuated the schisandrin response. The role of nitric oxide (NO) was confirmed by an increase in colonic NO production after schisandrin incubation, and the inhibition on the schisandrin responses by soluble guanylyl cyclase inhibitor 1H-[1,2,4] oxadiazolo[4,3-α]-quinoxalin-1-one (1-30 μM). Non-nitrergic NANC components may also be involved in the action of schisandrin, as suggested by the significant inhibition of apamin on the schisandrin-induced responses. Pyridoxal phosphate-6-azo(benzene-2,4-disulfonic acid) tetrasodium salt hydrate (100 μM), a selective P2 purinoceptor antagonist, markedly attenuated the responses to schisandrin. In contrast, neither 8-cyclopentyl-1,3-dipropylxanthine, an antagonist for adenosine A₁ receptors, nor chymotrypsin, a serine endopeptidase, affected the responses. All available results have demonstrated that schisandrin produced NANC relaxation on the rat colon, with the involvement of NO and acting via cGMP-dependent pathways. ATP, but not adenosine and VIP, likely plays a role in the non-nitrergic, apamin-sensitive component of the response.

Effect of schisandrin B on lung mRNA expression of transforming growth factor-beta1 signal transduction molecule in rat lungs exposed to silica

To investigate the effects of schisandrin B (Sch-B) on expression of transforming growth factor-beta1 (TGF-beta1) and signal transduction molecule mRNA in rat lungs exposed to SiO2, and explore the intervention mechanism of Sch-B on pulmonary fibrosis induced by SiO2. Ninety six Wistar rats were randomly divided into control (normal saline) group, SiO2 group and SiO2 plus Sch-B group. The rats were exposed to SiO2 by direct tracheal instillation to establish the silicotic animal models. SiO2 group and SiO2 plus Sch-B group were treated with 1 ml SiO2 (50 mg/ml) for each rat From the first day after model establishment, SiO2 plus Sch-B group were orally given Sch-B (80 mg/kg) a day, control group and silica group were orally given olive oil. On the 3rd, 7th, 14th and 28th days after treatment, 8 rats in each group were sacrificed and samples were collected. The histo-pathological examination of lung was performed by HE staining. The expression levels of TGF-beta1, TGF-betaR II and Smad4 mRNA in the lung tissues were detected by RT-PCR. The results of histo-pathological examination showed that in SiO2 group, lung tissues were injured obviously; the alveolar inflammation with alveolus interval edema and inflammation cell infiltration appeared on the 3rd and 7th days; the alveolus interval became thicker, became thicker, fibroblast and collagen matrix increased markedly on 14th day; the alveolar structure was damaged, alveolar wall thickened obviously, collagen aggravation and pulmonary fibrosis displayed on 28th day. The alveolar inflammation and pulmonary fibrosis in SiO2 plus Sch-B group were significantly less than those in SiO2 group. The expressions levels of TGF-beta1 TGF-betaR II and Smad4 mRNA (TGF-1beta: 1.03 +/- 0.31, 1.33 +/- 0.39,1.08 +/- 0.26, 0.82 +/- 0.16, TGF-betaR II: 0.65 +/- 0.11, 0.80 +/- 0.16, 0.83 +/- 0.24, 0.62 +/- 0.15, Smad4:0.87 +/- 0.15, 0.68 +/- 0.11, 0.78 +/- 0.19, 0.30 +/- 0.08) in SiO2 group were significantly higher than those in the control group (TGF-beta1:0.59 +/- 0.22, 0.55 +/- 0.25, 0.56 +/- 0.20, 0.55 +/- 0.12, TGR-betaR II :0.28 +/- 0.13, 0.31 +/- 0.15, 0.34 +/- 0.15, 0.27 +/- 0.09, Smad4:0.23 +/- 0.11, 0.40 +/- 0.12, 0.39 +/- 0.12, 0.18 +/- 0.06) (P < 0.01 or P < 0.05), but the expression level of TGF-beta1 mRNA was the highest on the 7th day. The expression levels of TGF-beta1 and Smad4 mRNA (TGF-beta1:0.68 +/- 0.28, 0.88 +/- 0.25, 0.75 +/- 0.11, 0.61 +/- 0.14,Smad4:0.25 +/- 0.12, 0.45 +/- 0.09, 0.44 +/- 0.07, 0.21 +/- 0.04) in SiO2 plus Sch-B group were significantly lower than those in SiO2 group (P < 0.01 or P < 0.05 ), but there were no significant differences of the TGFbetaR II mRNA expression levels between SiO2 group and SiO2 plus Sch-B group. Sch-B can reduce the pulmonary fibrosis induced by SiO2 through inhibition of the mRNA express of TGF-beta1 and Smad4 in the lung tissue, modulating the TGF-beta1/Smad4 signal transduction pathway and inhibiting the target gene activation.

Schisandrin B protects against solar irradiation-induced oxidative injury in BJ human fibroblasts

The effects of schisandrin B (Sch B) and its analogs on solar irradiation-induced oxidative injury were examined in BJ human fibroblasts. Sch B and schisandrin C (Sch C) increased cellular reduced glutathione (GSH) level and protected against solar irradiation-induced oxidative injury. The photoprotection was paralleled by decreases in the elastases-type protease activity and matrix-metalloproteinases-1 expression in solar-irradiated fibroblasts. The cytochrome P-450-mediated metabolism of Sch B or Sch C caused ROS production. The results suggest that by virtue of its pro-oxidant action and the subsequent glutathione antioxidant response, Sch B or Sch C may offer the prospect of preventing skin photo-aging.

Schisandrin B co-treatment ameliorates the impairment on mitochondrial antioxidant status in various tissues of long-term ethanol treated rats

The effect of schisandrin B (Sch B) on long-term ethanol-induced oxidative stress in various rat tissues was investigated. Long-term ethanol treatment increased reactive oxygen metabolites (ROM) level in plasma. The ethanol-induced oxidative stress was assessed by mitochondrial glutathione and α-tocopherol levels, antioxidant enzyme activities, malondialdehyde (mtMDA) production and heat shock protein (Hsp) 25/70 levels. Liver was most susceptible to oxidative stress with a significant increase in mtMDA production. Long-term Sch B treatment enhanced mitochondrial antioxidant status in a tissue non-specific manner. Sch B co-treatment ameliorated the alterations in plasma ROM levels, mtMDA production and Hsp 25/70 expression in rat tissues.

Effects of schisandrin on transcriptional factors in lipopolysaccharide-pretreated macrophages

Schisandrin is the main active ingredient isolated from Schisandra chinensis Baill. Recent studies have demonstrated that schisandrin exhibits anti-inflammatory effects in vivo and in vitro. In this study, we examined whether the order of lipopolysaccharide (LPS) treatment affects the mechanism of schisandrin anti-inflammatory activity. We found that the antiinflammatory mechanisms are not the same depending on whether macrophages were treated with schisandrin before or after LPS. The main difference is that inhibitor kappaBalpha (IkappaBalpha) degradation was not inhibited when macrophages were pretreated by LPS before schisandrin and was weakly inhibited when macrophages were pretreated by schisandrin before LPS.

Schisandrin B stereoisomers protect against hypoxia/reoxygenation-induced apoptosis and inhibit associated changes in Ca 2+-induced mitochondrial permeability transition and mitochondrial membrane potential in H9c2 cardiomyocytes

The effects of schisandrin B stereoisomers, (±)γ-schisandrin [(±)γ-Sch] and (−)schisandrin B [(−)Sch B], on hypoxia/reoxygenation-induced apoptosis were investigated in H9c2 cardiomyocytes. Changes in cellular reduced glutathione (GSH) levels, Ca 2+-induced mitochondrial permeability transition (MPT), and mitochondrial membrane potential (Δ ψ m) values, were examined in (±)γ-Sch-pretreated and (−)Sch B-pretreated cells, without or with hypoxia/reoxygenation challenge. The (±)γ-Sch and (−)Sch B (2.5–5.0 µM) pretreatments protected against hypoxia/reoxygenation-induced apoptosis of H9c2 cells in a concentration-dependent manner, with (−)Sch B being more potent. The degrees of protection decreased, however, at the higher drug concentrations of 7.5 µM in both (±)γ-Sch-pretreated and (−)Sch B-pretreated cells. The anti-apoptotic effects of the drugs were further evidenced by the suppression of hypoxia/reoxygenation-induced mitochondrial cytochrome c release and the subsequent cleavage of caspase 3 and poly-ADP-ribose polymerase after (−)Sch B pretreatment. Both (±)γ-Sch and (−)Sch B pretreatments increased GSH levels in H9c2 cells, with (−)Sch B being more potent. Hypoxia/reoxygenation challenge caused a depletion in cellular GSH and the cytoprotection afforded by (±)γ-Sch/(−)Sch B was associated with enhancement of cellular GSH in H9c2 cells, as compared to the drug-unpretreated control. Whereas hypoxia/reoxygenation challenge increased the extent of Ca 2+-induced MPT pore opening and decreased Δ ψ m in H9c2 cardiomyocytes, cytoprotection against hypoxia/reoxygenation-induced apoptosis afforded by (±)γ-Sch/(−)Sch B pretreatments was associated with a decreased sensitivity to Ca 2+-induced MPT and an increased Δ ψ m in both unchallenged and challenged cells, as compared to the respective drug-unpretreated controls. The degrees of protection against apoptosis correlated negatively with the extents of Ca 2+-induced MPT ( r = − 0.615, P < 0.01) and positively with the values of Δ ψ m ( r = 0.703, P < 0.01) in (±)γ-Sch/(−)Sch B-pretreated and hypoxia/reoxygenation challenged cells. The results indicate that (±)γ-Sch/(−)Sch B pretreatment protected against hypoxia/reoxygenation-induced apoptosis in H9c2 cardiomyocytes and that the cytoprotection afforded by (±)γ-Sch/(−)Sch B may at least in part be mediated by a decrease in cellular sensitivity to Ca 2+-induced MPT, which may in turn result from enhancement of cellular GSH levels by drug pretreatments.